The present invention relates to an electronic compass. More specifically, the present invention relates to an electronic compass with a moveable sensor.
Electronic compasses are commonly used in vehicles as an aid for direction finding and navigation. An electronic compass may be positioned in a vehicle on the instrument panel, the rearview mirror, or at other locations within a vehicle. The positioning of the compass in the interior of a vehicle often determines how the compass is installed and packaged. For example, when an electronic compass is attached to an adjustable rearview mirror, the compass electronics package may be integrated with the mirror, while the magnetic sensors used by the electronic compass are normally fixed to a point on the vehicle that is stationary relative to the vehicle so as to avoid the loss of calibration when the mirror is moved. Accordingly, the magnetic sensor must often be wired remotely from the electronics mounted on the adjustable rearview mirror. This remote wiring is not aesthetically pleasing and increases the complexity of packaging for the electronic compass. It would be preferable to bundle all of the electronics for an electronic compass, including its magnetic sensors and electronics, in the same package. Thus, there is a need in the art for an electronic compass having a moveable magnetic sensor which can maintain its calibration.
In accordance with the present invention, an electronic compass is equipped with magnetic sensor position instrumentation which allows the magnetic sensors of the electronic compass to be moved relative to the vehicle while maintaining its calibration.
The instrumentation informs the compass electronics of any movement of the magnetic sensors relative to the vehicle so that this movement may be factored into the electronic compass directional calibration.
The magnetic sensor and position instrumentation are physically integrated into the electronics package for the electronic compass of the present invention, allowing the electronic compass to be unitarily packaged. This unitary packaging improves the aesthetic appearance of the electronic compass and allows it to be easily mounted on the interior of a vehicle. The unitary packaging also allows the electronic compass to be easily retrofitted in the automotive aftermarket.